It is known from U.S. Pat. No. 4,534,331 to determine when acceleration enrichment of the engine mixture is appropriate by sequential detection of engine inlet manifold pressure values (representing engine load values) having a predetermined characteristic. For example, acceleration enrichment could be provided when a predetermined number of sequential load values ascended in magnitude according to a specific relationship.
One important condition for the effectiveness of transition compensation during acceleration (or deceleration) is the actuality of the load information which is used to calculate the duration of injection. In a pressure system, the average pressure in the inlet manifold of the engine can, in a static case, be used to calculate load. Thus, in incremental systems, the average pressure is determined, for example by double sensing (at 180.degree. intervals), whereas in segmental systems the average pressure can be obtained by high-frequency integration of pressure over one suction period.
Published European patent publications 0,259,544 and 0,162,469 disclose an acceleration correction of the injection amount, based on the measured pressure in the intake and in dependence on detected intake pressure differences. The correction is an additive one and further dependent on engine parameters, for example, temperature.